1. Field of the Invention
This invention relates generally to data recording apparatuses and, more particularly, to a data recording apparatus, which is applied for digital cameras, audio recorders or the like, for recording external data into a removable recording medium.
2. Description of the Prior Art
In order to record data to such a recording medium as an optical disk, there is a need to first rotate the optical disk. A recordable state is first available after the rotation velocity of the disk has stabilized. Consequently, when using a disk as a recording medium, it takes longer in getting a recordable state after turning on a power as compared to the case using a semiconductor memory as a recording medium.
Consequently, in the conventional digital camera using a disk recording medium, even if the power is turned on, the shutter button is not allowed to operate before the disk rotation velocity has stabilized. If herein a photographic image is temporarily stored to a semiconductor memory of the digital camera, shutter-button operation is possible even before stabilization in rotational velocity. However, recording to the disk must be assured for a photographic image once stored within the semiconductor memory through operation of the shutter button. In other words, in a state that a vacant capacity of the disk is less than a vacant capacity of the semiconductor memory, the shutter button should not be activated for operation. That is, whether to activate the shutter-button or not must be determined based upon a vacant capacity of the disk. In conclusion, the shutter button has been impossible to operate before disk rotation velocity has stabilized followed by reading a vacant capacity out of the disk.
Meanwhile, in the prior art it takes long in indicating the number of recordable frames, because the number of recordable frames is to be first calculated after detecting a vacant capacity.
Therefore, it is an primary object of the present invention to provide a data recording apparatus which can commence to fetch data even before a recordable state becomes available.
Another object of the invention is to provide a data recording apparatus which can output information related to a vacant capacity immediately after turning on a power.
According to the present invention, a data recording apparatus having a slot for receiving therein a removable recording medium including a first semiconductor memory and a disk, to record data fetched by a fetcher and temporarily stored in a second semiconductor memory to the disk, comprises: a vacant capacity value writer for writing a first vacant capacity value of the disk to the first semiconductor memory after the data have been recorded; a vacant capacity value reader for reading the first vacant capacity value out of the first semiconductor memory when turning on a power; and a restricter for restricting an amount of data to be fetched by the fetcher on the basis of the first vacant capacity value read out by the vacant capacity value reader.
The data fetched by the fetcher, after temporarily stored in the second semiconductor memory, is recorded on a disk included within the recording medium received in the slot. Herein, the vacant capacity writer writes a first capacity value of the disk to the first semiconductor memory included in the recording medium after the data has been recorded. The vacant capacity value written in the first semiconductor memory is read out by the vacant capacity reader in response to turning on the power in the next time. The amount of data to be fetched by the fetcher is restricted based on the first vacant capacity value by the restricter. Consequently, data fetching can be commenced even before a recordable state becomes available.
The restricter preferably includes a comparator to compare a second vacant value of the second semiconductor memory with the first vacant capacity value, and an invalidator for making invalid the second semiconductor memory in a portion exceeding the first vacant capacity value depending upon a result of comparison by the comparator.
In a preferred embodiment of the invention, a starter starts up the disk after turning on the power. A determiner determines whether or not the disk has stabilized in rotation velocity. After the rotation velocity has stabilized, a recorder records the data stored on the second semiconductor memory to the disk.
In another preferred embodiment of the invention, the fetcher includes a picture-taker to take a picture of a subject and a compressor to compress image data taken by the picture-taker. The second semiconductor memory stores image data compressed by the compressor. In a further preferred embodiment, a number-of-recordable-frames calculator calculates the number of recordable frames on the basis of the first vacant capacity value read out by the vacant capacity value reader. An indicator indicates the number of recordable frames.
In still another embodiment of the invention, a marker writer writes a predetermined marker to the first semiconductor memory after the data have been recorded. A marker determiner determines whether or not the predetermined marker exists on the first semiconductor memory when the power is turned on. A disabler disables the fetcher for a predetermined time depending upon a result of determination by the marker determiner. Herein, the predetermined time is a time for which the disk comes into stabilization in rotation velocity.
According to the present invention, a data recording apparatus having a slot for receiving therein a removable recording medium including a semiconductor memory and a disk, to record data fetched by a fetcher to the disk, comprises: a vacant capacity value writer to write a vacant capacity value of the disk to the semiconductor memory after the data have been recorded; a vacant capacity value reader to read the vacant capacity value out of the semiconductor memory when a power is turned on; and an outputter to output information related to the vacant capacity value read out by the reader.
The data fetched by the fetcher is recorded to the disk included within the recording medium received in the slot. Completing the recording, a vacant capacity value is written to the semiconductor memory by the vacant capacity value writer. The vacant capacity value reader reads a vacant capacity value from the semiconductor memory in response to turning on the power in the next time. The outputter outputs information related to the read vacant capacity value. Consequently, it is possible to output information related to a vacant capacity value immediately after turning on the power.
In a preferred embodiment of the invention, the fetcher includes a picture-taker to take a picture of a subject, the outputter including a calculator to calculate the number of recordable frames on the basis of the vacant capacity value, and an indicator to indicate the number of recordable frames.
The above described objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.